feat: run warmup requests on runtime startup to ensure that service is ready to accept connections

[girishc13]

Describe the feature

Warm up requests are executed before the service is reported ready so that new incoming requests can be readily served without having to create new network connections to database dependency or sidecar container, etc or load the required modules. Warm up requests can be dummy or canary or health check type requests that can trigger the hot path at least once. Warm up requests don't need to be successful but need to be executed before reporting readiness.

Your proposal

Gateway Runtime: execute service discovery request to all executors.
Executor Runtime: execute empty post request on the default endpoint.

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Environment

Screenshots